It is well known in the art to cause an electromagnetic beam to reflect from a sample, and by monitoring change in, for example, the intensity and/or polarization state of said beam resulting from interaction with the sample, determine properties of the sample, (e.g. thickness of thin films on the sample surface, and optical constants). It is also known that where a sample surface reflects specularly essentially all incident electromagnetic radiation can be reflected from the sample into a detector and good data will typically be developed thereby. A problem can occur, however, where a sample has an irregular surface, as incident electromagnetic radiation becomes scattered by what amounts to the effects of said beam effectively approaching the sample surface at different angles and planes of incidence, at different locations thereon. When this occurs a large majority of the electromagnetic radiation which reflects from the sample surface is often directed other than into a detector, or is scattered, rather than specularly reflected thereinto, which scattered electromagnetic radiation causes problems in analysis of acquired data. The intensity of a collected portion of a reflected beam can then become too weak to be used in sample analysis and attempts to increase the intensity entering a detector, without consideration of from where on an irregular sample surface the additional collected electromagnetic radiation reflects, can lead to data which is noisy, depolarized, based on uncertain angles-of-incidence, and therefore can not be reliably analyzed to provide good results.
To provide insight to priority it is disclosed that this application is a CIP of Pending application Ser. No. 11/980,262 Filed Oct. 30, 2007, which is a CIP of Pending application Ser. No. 11/495,130 Filed Jul. 29, 2006, and therevia this application is a Divisional of patent application Ser. No. 11/177,207 Filed Jul. 8, 2005; and therevia a CIP of 10/652,696 Filed Sep. 2, 2003, (now U.S. Pat. No. 7,230,699); and therevia claims Benefit of Provisional Application Ser. No. 60/459,690 Filed Apr. 3, 2003. This Application also, via the foregoing Applications, claims Benefit of Provisional Application Ser. No. 60/588,315 Filed Jul. 15, 2004. This Application further is a CIP of Co-Pending application Ser. No. 11/145,470 Filed Jun. 6, 2005, and therevia this application is a CIP of 10,376,677 Filed Feb. 28, 2003 (now U.S. Pat. No. 6,982,789), and therevia of Ser. Nos. 10/178,723 Filed Jun. 24, 2002, (now U.S. Pat. No. 6,950,182); Ser. No. 09/531,877 Filed Mar. 21, 2000; 09/583,229 Filed May 30, 2000, (now U.S. Pat. No. 6,804,004); 09/864,840 Filed May 24, 2001, (now U.S. Pat. No. 6,456,376); 10/943,821 Filed Sep. 17, 2004; 09/854,548 Filed May 14, 2001; and this application claims benefit of Provisional Application Ser. Nos. 60/300,714 Filed 0.06/26/01; 60/424,589 Filed Nov. 7, 2002; 60/427,043 Filed Nov. 18, 2002; 60/431,489 Filed Dec. 6, 2002.
It is noted that the most recent 262 Pending Application invention relates to systems for adjusting sample orientation, and more particularly to system and method for orienting the tilt and vertical position of samples in ellipsometer and the like systems. As mentioned above, it is known to place samples on stages in ellipsometer and the like systems, and to cause a polarized beam of electromagnetic radiation to impinge on said sample at an oblique angle thereto, interact with said sample and then enter a detector. It is also known that the “tilt” of a sample surface at a specific location thereon can affect realized angle and plane-of-incidence values actually achieved. Further, it is known to adjust the vertical height of the stage to position a sample such that a beam of electromagnetic radiation reflecting therefrom enters a detector. And, it is known to use a beam of electromagnetic radiation comprising a range of wavelengths, (e.g. which can be smaller or larger than a facet feature on a sample to enable), investigation thereof).
Existing Provisional and Utility Applications, (i.e. 60/459,690 Filed Apr. 3, 2003 and Allowed application Ser. No. 10/652,696 Filed Sep. 2, 2003, now U.S. Pat. No. 7,230,699), by an Inventor herein, show a prior art system for detecting sample tilt, and a system which utilizes an ellipsometer beam reflected from a sample to perform vertical positioning of a stage. Importantly, FIG. 3b, therein, (presented as FIG. 3c herein), shows a sample which is very much the same as the textured faceted samples investigated by the present invention when rotated to a different orientation. The stage in said 699 Patent FIG. 3a, (presented as FIG. 3d herein), is shown as being rotatable in Angle-of-Incidence (AOI) Tip, Plane-of-Incidence (POI) Tilt and about a normal to the surface of the stage (STG), (and if present thereupon a specular sample). To point out differences between the 699 Patent system and the present invention, it is disclosed that the 669 Patent describes a beam splitter which is used to divert a portion of the reflected beam into a detector and used to mediate adjustment of the sample's vertical position and/or tilt. Said system does not secure relative position of the ellipsometer and sample, but provides for aligning a sample system and controlling the angle and plane-of-incidence at which a beam of electromagnetic radiation obliquely impinges on a monitored location of a surface of a sample, and comprises, as viewed in side elevation:                a sample supporting stage which can be translated in “X”, “Y” or “Z” directions as well as rotated about “X”, “Y” and optionally “Z” axes; vertically above said stage there being a first beam splitter means, a lens and a first camera means for providing a view of a portion of the surface of said sample, said first beam splitter means optionally having positioned on a lower surface thereof light emitting means for providing light to the surface of said sample;        laterally with respect to said first beam splitter means there being a reflection means;        vertically above said reflection means there being a second beam splitter;        vertically above said second beam splitter there being a second camera means and laterally with respect to said second beam splitter, there being sequentially a lens and an essentially point source of electromagnetic radiation;        said first and second camera means each having associated therewith display means.        Said system further comprises an ellipsometer polarization state generator to cause, and a polarization stage detector to monitor, a beam of electromagnetic radiation which in use impinges on said monitored location on said surface of said sample at an oblique angle thereto.        In use said first camera means and its associated display means provide a view of at least a portion of the surface of a sample utilizing light provided by said light emitting means for providing light to the surface of said sample positioned on said lower surface of said first beam splitter, and said essentially point source of electromagnetic radiation provides electromagnetic radiation to the surface of said sample via said second beam splitter, said reflective means and said first beam splitter, and said sample supporting stage is caused to be translated in any of said “X”, “Y” and “Z” directions as well as rotated about said “X”, “Y” and optionally “Z” axes which are necessary to cause an interrogating beam of electromagnetic radiation provided by said essentially point source of a source of electromagnetic radiation to reflect from the surface of said sample, proceed back through said first beam splitter means, reflect from said reflective means, pass through said second beam splitter means, enter said second camera means and cause an image on the display means associated therewith which indicates that the monitored location on the sample surface is oriented so as to face substantially vertically.        The purpose of the foregoing is to align said sample surface to assure that said beam of electromagnetic radiation provided to said monitored location on the surface of said sample at an oblique angle approaches said surface at known intended angle-of-incidence and plane-of-incidence orientation, rather than at an angle-of-incidence and plane-of-incidence orientation which is modified by surface irregularities or non-flat samples.        
Said system can further comprise a polarizer means in the path of said beam of electromagnetic radiation provided by said essentially point source of electromagnetic radiation, and in which said first beam splitter is sensitive to polarization state, and the polarizer means can be adjustable to enable control of the direction of polarization. The system point source of a source of electromagnetic radiation can comprise a fiber optic. The related Co-Pending 130 application describes a related system.
Continuing, as it is relevant, patent to Abraham et al., U.S. Pat. No. 6,091,499 is disclosed as it describes a method and system for automatic relative adjustment of samples in relation to an ellipsometer. Paraphrasing, said Abraham et al. system basically comprises:                a system for orienting a sample on a stage in an ellipsometer system comprising a first light source, a polarizer, said stage, an analyzer and a detector;        said system further comprising a detection system having a second light source, wherein said detection system is independently adjustable in relation to said ellipsometer, and wherein said detection system can be electronically locked into position relative to said ellipsometer so that said ellipsometer and said detection system can be adjusted as one unit in relationship to said stage, wherein said detection system can detect both a tilt of a sample placed onto said stage, and a distance of said sample from a coordinate source of the ellipsometer in two perpendicular axes; and        said system further comprising an adjusting device, wherein said adjusting device can adjust tilt of said stage, and wherein said adjusting device can adjust the position of said ellipsometer and detection system when in an electronically locked relationship with respect to one another.        
The 499 Patent drawings show a single source, (identified as (21)), provides, via beam splitters and reflection means, normal and oblique angle-of-incidence electromagnetic beams to a sample, which normal and oblique angle-of-incidence electromagnetic beams are each intercepted by a different detector, (identified as (24) and (25) respectively), after reflecting from the sample. The associated ellipsometer system comprises a separate source, (identified as (11)).
Additional known related Patents are:                Patent to Coates U.S. Pat. No. 4,373,817;        Patent to Coates U.S. Pat. No. 5,045,704;        RE. 34,783 to Coates;        Patent to Mikkelsen et al., U.S. Pat. No. 6,600,560;        Patent to Fanton et. al., U.S. Pat. No. 5,596,411;        Patent to Piwonka-Corle et al., U.S. Pat. No. 5,910,842;        Patent to Piwonka-Corle et al., U.S. Pat. No. 5,608,526;        Patent to Bareket, U.S. Pat. No. 5,889,593;        Patent to Norton et al., U.S. Pat. No. 5,486,701;        Patent to Aspnes et al., U.S. Pat. No. 5,900,939;        Patent to Aspnes et al., U.S. Pat. No. 5,798,837;        Patent to Rosenscwaig et al., U.S. Pat. No. 5,412,473;        Patent to Carter et al., U.S. Pat. No. 5,771,094;        Patent to Liphardt, U.S. Pat. No. 7,136,162;        PCT Application Publication WO 99/45340;        Published Application of Stehle et al., No. US2002/0024668 A1.        
Additionally, a recent computer search using the words “solar cell” and “sample tilt” provided no hits, while using the words “solar cell” and “substrate tilt” provided one hit each for Patents and Published Applications, (e.g. U.S. Pat. No. 5,388,635 and Published Application US 2007/0267711), and using the words “solar cell” and “stage tilt” provided two hits each for Published Applications, (e.g. US 2006/0048800 and 2004/0056779). None of these identified references are considered relevant.
Provisonal Application Ser. No. 61/126,233 filed May 2, 2008 in incorporated herein by reference.
Finally, while there is no known published disclosure thereof, Applicants have heard, “through the grapvine”, that another entity (i.e. Sentech), is using a large sample tilt technique similar to that disclosed herein, to facilitate investigation of solar cells. However, Applicants believe this alternative use is of very recent implementation and, for instance, does not involve use of spectroscopic electromagnetic radiation nor involve application of a sample stage rotation.
An approach to investigating a sample with a “regularly” textured surface, (i.e. it comprises a surface having a repeated faceted pattern thereupon) and/or a surface characterized by an irregular array of faceted structures, would provide utility. If possible, such an approach would allow a researcher to collect an increased amount of “information containing” electromagnetic radiation which reflects from said sample textured surface and enters a detector to produce good data. It is such an approach that is subject of the present invention.